Cysts, fibrocystic breast changes, fibroadenomas, infections and injuries can cause noncancerous breast lumps. You may find several types of breast lumps, most of them harmless (benign), during your monthly cycles. Only your doctor can tell you which type you have.
- Cysts. If you find a lump that feels round, smooth and firm, it could be a cyst. A cyst is a dilated milk duct filled with fluid. It may be tiny or large, and the surrounding area may be tender. Your cyst may appear before your menstrual period and decrease in size or disappear afterward.
- Fibrocystic breast changes. You may feel fullness in your breasts with areas of lumpiness and tenderness or pain. Nearly half of women have such fibrocystic changes related to their menstrual cycles.
- Fibroadenomas. Some benign lumps are solid, smooth and easy to move around. If you find one of those common lumps, it may be a fibroadenoma. If you're pregnant or using hormones, the lump may get larger. It's important to have a new lump evaluated. Sometimes a physical exam doesn't tell your doctor whether you have a cyst or a solid lump. Then, your doctor may need to order breast imaging, such as a mammogram or ultrasound. Your doctor may recommend a breast biopsy based on your clinical exam and imaging.
- Infections and injuries. A severe injury to your breast tissue or nearby nerves can create a lump. This is often described as fat necrosis. If it doesn't go away, you need to have a doctor evaluate it.
- Breast cancer. If you have a lump that is painless, hard and irregular, and different from the surrounding breast tissue, it might be breast cancer. Your skin over the lump may be retracted, or the skin might look red, dimpled, or pitted like the skin of an orange. Your breast size or shape may change, or you may notice discharge from the nipple.
Read more about breast cysts, fibrocystic breasts, fibroadenomas, breast cancer and male breast cancer at MayoClinic.com.